Fire resistant corespun yarn and fabric comprising same

ABSTRACT

Provided is a fire resistant corespun yarn. The yarn includes a core of a high temperature resistant continuous filament comprising fiberglass and a low temperature synthetic continuous filament selected from nylon, polyester, polyethylene and polyolefin, the core being two-plied. A first sheath of blended staple fibers surrounds the core. The fibers include modacrylic fibers and melamine fibers. A second sheath of staple fibers surrounds the first corespun yarn. This double corespun yarn may be woven and knit in fine, non-plied or plied form and extends the range of fineness of fabrics below heretofore achievable limits. Also provided is a fire resistant fabric which includes a fire resistant fabric substrate formed from the fire resistant corespun yarn, as well as a product upholstered with the fire resistant fabric.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to a fire resistant yarn and to a method ofpreparing a fire resistant yarn. The invention also relates to a fabricwhich includes the fire resistant yarn. The invention has particularapplicability in the formation of fire resistant fabrics forapplications such as upholstery, mattress and pillow ticking, bedspreads, pillow covers, draperies or cubicle curtains, wallcoverings,window treatments and baby clothing.

[0003] 2. Description of the Related Art

[0004] It is well known in the textile industry to produce fireresistant fabrics for use as upholstery, mattress ticking, panel fabricand the like, using yarn formed of natural or synthetic fibers, and thentreating the fabric with fire retarding chemicals. Conventional fireretarding chemicals include halogen-based and/or phosphorus-basedchemicals. Unfortunately, such treated fabric is heavier than similartypes of non-fire retardant fabrics, and further has a limited wearlife. Also, this type of fabric typically melts or forms brittle charswhich break away when the fabric is burned, and exposes the foam of acomposite chair, mattress or panel fabric system. The exposed foam thenacts as a fuel source.

[0005] It is also known to form fire resistant fabrics of fireresistant, relatively heavy weight yarns in which a low temperatureresistant fiber is ring spun around a core of continuous filamentfiberglass. However, this type of ring spun yarn has torque impartedthereto during the spinning process and is very lively. Because of thelively nature of the yarn, it is necessary to ply AS≅ and AZ≅ ring spunyarns together so that the torque and liveliness in the yarn is balancedin order to satisfactorily weave or knit the yarn into the fabric,without experiencing problems of tangles occurring in the yarn duringthe knitting or weaving process. This plying of the “S” and “Z” yarnstogether results in a composite yarn which is so large that it cannot beused in the formation of fine textured, lightweight fabrics. In someinstances, the fiberglass filaments in the core protrude through thenatural fiber sheath. It is believed that the problem of protruding corefibers is associated with the twist, torque and liveliness beingimparted to the fiberglass core during the ring spinning process.

[0006] It is the current practice to produce coated upholstery fabricsby weaving or knitting a substrate or scrim of a cotton or cotton andpolyester blend yarn. This scrim is then coated with a layered structureof thermoplastic polyvinyl halide composition, such as polyvinylchloride (PVC). This coated upholstery fabric has very little, if any,fire resistance and no flame barrier properties. In addition to thecoating chemical having a limited shelf life, the chemical coatings aredisadvantageous in that they pose a safety hazard in case of contactwith skin.

SUMMARY OF THE INVENTION

[0007] To overcome or conspicuously ameliorate the disadvantages of therelated art, it is an object of the present invention to provide a novelfire resistant corespun yarn. As used herein, the term “fire resistant”means that when, in the form of a woven or a knitted fabric composedentirely of the yarn, it satisfies the requirements of the standardTechnical Bulletin, California 133 Test Method (Cal. 133).

[0008] It is a further object of the invention to provide a fireresistant fabric which includes the fire resistant corespun yarn in afire resistant fabric substrate.

[0009] It is a further object of the invention to provide a productupholstered with the fire resistant fabric.

[0010] The corespun yarn can advantageously be used in forming finetextured or non-textured fire resistant decorative fabrics. Uponexposure to flame and high heat, sheathings of staple fibers surroundingand covering a core become charred and burnt, yet remain in positionaround the core to create a thermal insulation barrier. The chareffectively can block the flow of oxygen and other gases, preventing thefabric from igniting.

[0011] In addition, the fabrics woven or knit with the corespun yarn ofthe present invention can advantageously be dyed and printed withconventional dying and printing materials. These fabrics areparticularly suitable for forming fine textured fire resistant flamebarrier decorative fabrics for use in upholstery, panel fabrics,mattress and pillow ticking, draperies or cubicle curtains,wallcoverings, window treatments and baby clothing.

[0012] In accordance with a first aspect of the invention, a fireresistant corespun yarn is provided. The corespun yarn includes a coreof a high temperature resistant continuous filament comprisingfiberglass. A first sheath of blended staple fibers surrounds the core,the fibers including modacrylic fibers and melamine fibers. A secondsheath of staple fibers surrounds the first corespun yarn.

[0013] In accordance with a particularly preferred embodiment of theinvention, the core has a structure which includes a low temperatureresistant continuous filament synthetic fiber selected from the groupconsisting of polyethylene, nylon, polyester and polyolefin, two-pliedwith the fiberglass filament.

[0014] In accordance with a further aspect of the invention, a fireresistant corespun yarn is provided. The corespun yarn includes atwo-plied core of a high temperature resistant continuous filamentcomprising fiberglass and a low temperature resistant continuousfilament synthetic fiber selected from the group consisting ofpolyethylene, nylon, polyester and polyolefin. A first sheath of blendedstaple fibers surrounds the core, the fibers including modacrylic fibersand melamine fibers. A second sheath of staple fibers surrounds thefirst corespun yarn. The core accounts for from about 15 to 35% byweight based on the total weight of the corespun yarn, and the secondsheath accounts for from about 35 to 80% by weight based on the totalweight of the corespun yarn.

[0015] In accordance with yet another aspect of the invention, a fireresistant fabric is provided. The fabric includes a fire resistantfabric substrate, which includes the fire resistant corespun yarn.

[0016] In accordance with yet another aspect of the invention, a productupholstered with the fire resistant fabric is provided. The product canadvantageously be free of a fire resistant coating and of a barrierfabric.

[0017] Other objects, advantages and aspects of the present inventionwill become apparent to one of ordinary skill in the art on a review ofthe specification, drawings and claims appended hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The objects and advantages of the invention will become apparentfrom the following detailed description of the preferred embodimentsthereof in connection with the accompanying drawings, in which likenumerals designate like elements, and in which:

[0019]FIG. 1 is an enlarged view of a fragment of the balanced doublecorespun yarn in accordance with the present invention;

[0020]FIG. 2 is a schematic diagram of an air jet spinning apparatus ofthe type utilized in forming the fine denier corespun yarn and doublecorespun yarn of the present invention; and

[0021]FIG. 3. is a fragmentary isometric view of a portion of a wovenfabric in accordance with invention;

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0022] Preferred embodiments of the invention will now be described withreference to FIG. 1, which illustrates an exemplary fire resistantmulti-corespun yarn in accordance with one aspect of the invention.While the exemplary fire resistant yarn is a balanced double corespunyarn, it should be clear that triple or more corespun yarns are alsoenvisioned.

[0023] The basic structure of the yarn 100 in accordance with theinvention includes a filament core 102 completely surrounded by a firstsheath 104, and a second sheath 106 completely surrounding the firstsheath 104.

[0024] Core 102 is formed from a high temperature resistant continuousfilament fiberglass 108, two-plied with a low temperature resistantcontinuous filament synthetic fiber 110. The core 102 is preferably fromabout 15 to 35% by weight based on the total weight of the corespunyarn.

[0025] Suitable continuous filament fiberglass materials for use in thecore 102 are commercially available, for example, from PPG. The filamentfiberglass 108 is preferably from about 10 to 30% by weight of the totalweight of the double corespun yarn 100.

[0026] Preferably, synthetic fiber 110 is formed of a synthetic (i.e.,man made) material selected from the group consisting of a polyethylene,a nylon, a polyester and a polyolefin. Of these, nylon is particularlypreferred. Suitable continuous synthetic fiber filaments arecommercially available, for example, continuous filament nylon fromBASF. Synthetic fiber 110 is preferably from about 5 to 25% by weight ofthe total weight of the double corespun yarn 100. While a two-plied corestructure has been exemplified, it should be clear that othermulti-plied core structures can be used.

[0027] First sheath 104 is a medium to high temperature staple fiberblended sheath. The fiber blend comprises two or more different types ofsynthetic fibers which include blended modacrylic and melamine staplefibers surrounding the two-plied core 102. Modacrylic fiber is a stablefiber which chars and expands when exposed to open flame, while melaminefiber is a high temperature resistant, unstable brittle fiber. Themodacrylic fiber acts as a carrying agent for the melamine fiber which,when blended, creates a stable/flexible high temperature resistantmaterial. Suitable modacrylics are sold under the tradenames Protex7 (M)or Protex7 (S), while melamine fiber is commercially available from BASFunder the tradename Basofil7.

[0028] In the fiber blend, the modacrylic staple fibers preferablyaccount for from about 50 to 90% by weight of the total weight of thefirst sheath, while the melamine fibers preferably account for fromabout 10 to 50% by weight of the total weight of the first sheath. Thefirst sheath 104 is preferably from about 10 to 40% by weight of thetotal weight of the double corespun yarn 100.

[0029] Second sheath 106 is a low to medium temperature chopped staplefiber sheath surrounding the core 102 and first sheath 104 (i.e., thefirst core spun yarn) to create the product double sheath corespun yarn100. The low to medium temperature resistant staple fibers of the secondsheath 106 are preferably selected from a variety of different types ofeither natural (e.g., vegetable, mineral or animal) or synthetic fibers,such as cotton, wool, nylon, polyester, polyolefin, rayon, acrylic,silk, mohair, cellulose acetate, or blends of such fibers. Of these, thepreferred low to medium temperature resistant staple fibers are cottonor polyolefin. The second sheath 106 is preferably from about 35% to 80%of the total weight of the double corespun yarn 100.

[0030] The two-plied continuous fiberglass and synthetic filaments 108,110 of the core 102 extend generally longitudinally in an axialdirection of the double corespun yarn 100. The majority of the staplefibers of the first sheath 104 and of the second sheath 106 extendaround core 102 in a slightly spiraled direction. A minor portion, forexample, from about 35 to 80%, of the staple fibers of each of thesheaths form a binding wrapper spirally around the majority of thestaple fibers, as indicated at 112, in a direction opposite the majorityof staple fibers. The first sheath 104 hence surrounds and completelycovers the two-plied core 102, and the second sheath 106 surrounds andcompletely covers the first sheath 104. The outer surface of the doublecorespun yarn has the appearance and general characteristics of the lowto medium temperature resistant fibers forming the second sheath 106.

[0031] The size of the product yarn will vary depending on the finalapplication of the yarn and the particular fabric characteristicsdesired, but is preferably within the range of from about 30/1 to 1/1conventional cotton count, preferably from about 21/1 to 10/1conventional cotton count.

[0032] The product multi-corespun yarn is balanced and has very littleif any torque or liveliness. This characteristic allows the yarn to bewoven or knitted in single end manner without the need for two ends tobe plied to balance the torque. As a result, fine textured fabrics canbe formed having heat resistant properties which have not been possibleto date.

[0033] A method for forming the double corespun yarn 100 in accordancewith the invention will now be described with reference to FIG. 2. Aspointed out above, the double corespun yarn 100 of the present inventionis preferably produced on an air jet spinning apparatus 200 of the typeillustrated. Such an apparatus is commercially available, for example,from Murata of America, Inc., and is described in the literature. See,e.g., U.S. Pat. Nos. 5,540,980, 4,718,225, 4,551,887 and 4,497,167, theentire contents of which patents are incorporated herein by reference.

[0034] The air jet spinning apparatus 200 includes an entrance trumpet202 into which a sliver of medium to high temperature resistant staplefibers 204 is fed. Staple fibers 204 are then passed through a set ofpaired drafting rolls 206. A continuous filament fiberglass and lowtemperature continuous filament synthetic two-plied core 102 is fedbetween the last of the paired drafting rolls 206 and onto the top ofthe staple fibers 204.

[0035] The two-plied core 102 and staple fibers 204 then pass through afirst fluid swirling airjet nozzle 210, and a second fluid swirling airjet nozzle 212, thereby forming a first corespun yarn 214. The first andsecond air jet nozzles 210, 212 are constructed to produce swirlingfluid flows in opposite directions, as indicated by the arrows. Theaction of first air jet nozzle 210 causes the staple fibers 204 to bewrapped or spiraled around the two-plied core 102 in a first direction.The oppositely operating air jet nozzles 210, 212 causes a minorportion, for example, from about 5 to 20%, of the staple fibers toseparate and wind around the unseparated staple fibers in a directionopposite the majority fiber spiral. The wound staple fibers maintain thefirst sheath 104 in close contact surrounding and covering the two-pliedcore 102. The first corespun yarn 214 is then drawn from the secondnozzle 212 by a delivery roll assembly 216 and is wound onto a take-uppackage (not shown).

[0036] The same air jet spinning apparatus can be utilized to apply thesecond sheath 106 to the first corespun yarn 214 in the same mannerdescribed above, thereby forming the double corespun yarn 100. In thisinstance, the low to medium temperature resistant staple fibers of thesecond sheath 106 are fed through the entrance trumpet 202, and thefirst corespun yarn 214 is passed through the set of paired draftingrolls 206. The same spiraling action achieved for the first sheath isobtained for the second sheath staple fibers around the first sheath byway of the oppositely operating air jet nozzles 210, 212. The secondcorespun yarn is then drawn from the second nozzle 212 by the deliveryroll assembly 216 and is wound onto the take-up package.

[0037] Since the formation of the present yarn on an air jet spinningapparatus does not impart excessive liveliness and torque to thetwo-plied fiberglass/synthetic core, no problems are experienced withloose and broken ends of the fiberglass/synthetic core protrudingoutwardly through the first sheath and or the second sheath in the yarnand the fabrics produced therefrom. Since it is possible to producewoven and knitted fabrics utilizing single ends of double corespun yarn,the double corespun yarn can be woven into fine textured fabrics withthe double corespun yarn being in the range of from about 30/1 to 1/1conventional cotton count. This extends the range of fineness of thefabrics which can be produced relative to the types of fabricsheretofore possible to produce by utilizing only double corespun yarnsof the prior art.

[0038] The flame resistant multi-corespun yarns described above canadvantageously be used in forming fine textured fire resistant barrierdecorative fabrics for numerous applications, such as upholstery,mattress and pillow ticking, bed spreads, pillow covers, draperies orcubicle curtains, wallcoverings, window treatments and baby clothing.FIG. 3 illustrates an enlarged view of a portion of an exemplary wovendecorative fabric 300 in a two up, one down, right-hand twill weavedesign. In this exemplified embodiment, the above-described flameretardant multi-corespun yarn is employed for warp yarns A. The materialfor the filling yarn can be the same or different from that of the warpyarn, depending on the second sheathing material. For purposes ofillustration, an open weave is shown to demonstrate the manner in whichthe warp yarns A and the filling yarns B are interwoven. However, theactual fabric can be tightly woven. For example, the weave can includefrom about 10 to 200 warp yarns per inch and from about 10 to 90 fillingyarns per inch.

[0039] While FIG. 3 illustrates a two up, one down, right-hand twillweave design, the described multi-corespun yarns can be employed in anynumber of designs. For example, the fabric can be woven into variousjacquard and doubly woven styles.

[0040] Fabrics formed with the described yarns have the feel and surfacecharacteristics of similar types of upholstery fabrics formed of 100%polyolefin fibers while having the desirable fire resistant and flamebarrier characteristics not present in upholstery fabric formed entirelyof polyolefin fibers. In this regard, the fabrics formed in accordancewith the invention meet various standard tests designed to test the fireresistancy of fabrics. For example, one standard test for measuring thefire resistant characteristics of fabrics is Technical Bulletin,California 133 Test Method (Cal. 133), the entire contents of which areherein incorporated by reference. According to this test, a compositemanufactured chair upholstered with a fabric to be tested is exposed toan 80 second inverted rectangular Bunsen burner flame. Fabrics employingthe above-described fire resistant multi-spun yarns having gone throughthis test remain flexible and intact, exhibiting no brittleness,melting, or fabric shrinkage. Additional tests which the formed fabricsmeet include the proposed Consumers Product Safety Commission (CPSC)Proposed Flammability Code, the Component Testing on Chair Contents(Britain, France, Germany and Japan) and the Component Testing onManufactured Chair (Britain, France, Germany and Japan).

[0041] When fabrics which have been formed of the balanced doublecorespun yarn of the present invention are exposed to flame and highheat, the first and second sheaths 104, 106 of staple fibers surroundingand covering the core are charred and burned but remain in positionaround the two-ply fiberglass/synthetic core 102 to create a thermalinsulation barrier. The fiberglass core and part of the first sheath 104of the modacrylic/melamine fiber blend remain intact after the organicstaple fiber materials from the second sheath 106 have burned. They forma lattice upon which the char remains, thereby blocking flow of oxygenand other gases through the fabric while providing a structure whichmaintains the integrity of the fabric after the organic materials of thestaple fiber first and second sheaths have been burned and charred.Unlike known fabrics, chemical treatment of the sheath or fabric fibersis not required because the composite multi-corespun yarn is inherentlyflame resistant. Non-flame retardant coatings may, however, be appliedto the surface or backing of the fabric to form a more dimensionallystable fabric depending on the end product use or composite fabric andproduct application.

[0042] Fabrics woven or knit of the double corespun yarn of the presentinvention may be dyed and printed with conventional dying and printingmaterials and methods since the outer surface characteristics of theyarn and the fabric formed thereof are determined by the second sheathof low to medium temperature resistant staple fibers surrounding thefirst sheath and covering the core.

[0043] This ability to dye the fabrics is quite surprising to personsskilled in the art given that the fiberglass cores in known fabrics areknown to explode during the dye process. This explosion phenomena isbelieved to be due to excessive heating of the fiberglass core togetherwith the diffusion of sodium into and reaction with the fiberglass coreduring the dye process. In this regard, the dye process is typicallyconducted under relatively high temperatures (e.g., 60 to 70EC), and thedye chemical is known to pass through the sheathing to the core of knownfabrics. Because of this problem, conventional fabrics are limited inpost-treatment coloration to various printing processes. Themodacrylic/melamine fibers of the first sheath are believed tosignificantly diffuse the fiberglass/synthetic two-plied core.Additionally, the first sheath is believed to dissipate heat such thatthe fiberglass filament is not overheated.

[0044] The following non-limiting examples are set forth to furtherdemonstrate the formation of multi-corespun yarns produced in accordancewith the present invention. These examples also demonstrate that fireresistant fabrics can be formed from these multi-corespun yarns.

EXAMPLES Example 1

[0045] A continuous filament fiberglass was two-plied with a continuousnylon fiber to form a core for the yarn. The fiberglass of the core wasECD 225 1/0 (equivalent to 198 denier) sold by PPG, and the nylon was 20denier 8 filament (equivalent to a 172 conventional cotton count) fromBASF. The core fiber materials had a weight such that the core accountedfor 25% by weight of the overall double spun yarn weight. The two-pliedcore was fed between the paired drafting rolls 206 of the air jetspinning apparatus illustrated in FIG. 2. At the same time, a blendedsliver of medium to high temperature resistant modacrylic (Protex7(M))/melamine (BASF Basofil7) fibers was fed into the entrance end ofthe entrance trumpet 202 to form a first corespun yarn. The blendedmodacrylic/melamine sliver had a weight of 45 grains per yard, and amodacrylic/melamine fiber blend of 50/50% by weight, which was obtainedby a Truetzschler multi-blending, carding and drawing process. Themodacrylic/melamine fibers had a weight such that the first sheathaccounted for 25% by weight of the overall double spun yarn weight. Thefirst corespun yarn had a conventional cotton yarn count of 20.

[0046] A second sheath material consisted of a 100% polyolefin sliverhaving a weight of 45 grains per yard and a denier of 532. Thepolyolefin fibers had a weight such that the second sheath accounted for50% by weight of the overall yarn weight. These fibers were fed into theentrance end of the entrance trumpet 202. At the same time, the firstcorespun yarn having a weight necessary to account for 50% by weight ofthe overall double spun yarn weight was fed between the paired draftingrolls 206. A double corespun yarn was thereby formed. The doublecorespun yarn achieved by this air jet process had a 10/1 conventionalcotton count.

Example 2

[0047] A continuous filament fiberglass was two-plied with a continuousnylon fiber to form a core for the yarn. The fiberglass of the core wasECD 450 1/0 (equivalent to 98 denier) sold by PPG, and the nylon was 20denier 8 filament (equivalent to a 172 conventional cotton count) fromBASF. The core fiber materials had a weight such that the core accountedfor 25% by weight of the overall double spun yarn weight. The two-pliedcore was fed between the paired drafting rolls 206 of the air jetspinning apparatus illustrated in FIG. 2. At the same time, a blendedsliver of medium to high temperature resistant modacrylic (Protex7(M))/melamine (BASF Basofil7) fibers was fed into the entrance end ofthe entrance trumpet 202 to form a first corespun yarn. The blendedmodacrylic/melamine sliver had a weight of 45 grains per yard, and amodacrylic/melamine fiber blend of 50/50% by weight, which was obtainedby a Truetzschler multi-blending, carding and drawing process. Themodacrylic/melamine fibers had a weight such that the first sheathaccounted for 25% by weight of the overall double spun yarn weight. Thefirst corespun yarn had a conventional cotton yarn count of 30.

[0048] A second sheath material consisted of a 100% polyolefin sliverhaving a weight of 45 grains per yard and a denier of 532. Thepolyolefin fibers had a weight such that the second sheath accounted for50% by weight of the overall yarn weight. These fibers were fed into theentrance end of the entrance trumpet 202. At the same time, the firstcorespun yarn having a weight necessary to account for 50% by weight ofthe overall double spun yarn weight was fed between the paired draftingrolls 206. A double corespun yarn was thereby formed. The doublecorespun yarn achieved by this air jet process had a 15/1 conventionalcotton count.

Example 3

[0049] The double corespun samples resulting from Examples 1 and 2 wereeach employed as the filling yarn in the woven process to form arespective fabric sample as illustrated in FIG. 3. The fabrics had 90warp yarns per inch and 40 filling yarns per inch. The double corespunyarn had a 10/1 conventional cotton count in the filling and a 15/1conventional cotton count in the warp to form an 8.5 ounce per squareyard, two up, one down, right-hand twill weave fabric.

[0050] The fabrics were subjected to the standard test described inTechnical Bulletin, California 133 Test Method (Cal. 133). The fabricswere each found to remain flexible and intact, exhibiting nobrittleness, melting, or fabric shrinkage. The second sheath ofpolyolefin fibers was burnt and charred. However, the charred portionsremained in position surrounding the core and the first sheath. Theseresults indicate that the two-plied core and first sheath effectivelyprovide a thermal insulation barrier and limited movement of vaporthrough the fabric, while, in addition, the fiberglass/synthetic coreand the first sheath modacrylic/melamine blend also provide a gridsystem, matrix or lattice which prevents rupture of the upholsteryfabric and penetration of the flame through the upholstery fabric andonto the material of which the chair was formed.

[0051] While the invention has been described in detail with referenceto specific embodiments thereof, it will be apparent to one skilled inthe art that various changes and modifications can be made, andequivalents employed, without departing from the scope of the appendedclaims.

What is claimed is:
 1. A fire resistant corespun yarn, comprising: acore of a high temperature resistant continuous filament comprisingfiberglass; a first sheath of blended staple fibers surrounding thecore, the fibers comprising modacrylic fibers and melamine fibers; and asecond sheath of staple fibers surrounding the first corespun yarn. 2.The fire resistant corespun yarn according to claim 1, wherein the corehas a multi-ply structure.
 3. The fire resistant corespun yarn accordingto claim 2, wherein the multi-ply structure comprises a low temperatureresistant continuous filament synthetic fiber selected from the groupconsisting of polyethylene, nylon, polyester and polyolefin, two-pliedwith the fiberglass filament.
 4. The fire resistant corespun yarnaccording to claim 1, wherein the second sheath staple fibers are of amaterial selected from the group consisting of cotton, wool, nylon,polyester, polyolefin, rayon, acrylic, silk, mohair, cellulose acetate,and blends thereof.
 5. The fire resistant corespun yarn according toclaim 4 wherein the second sheath staple fibers are cotton or polyolefinfibers.
 6. The fire resistant corespun yarn according to claim 5,wherein the core is from about 15 to 35% by weight based on the totalweight of the corespun yarn, and the second sheath is from about 35 to80% by weight based on the total weight of the corespun yarn.
 7. Thefire resistant corespun yarn according to claim 6, wherein the core isabout 25% by weight based on the total weight of the corespun yarn, andthe second sheath is about 50% by weight based on the total weight ofthe corespun yarn.
 8. The fire resistant corespun yarn according toclaim 1, wherein the size of the corespun yarn is from about 30/1 to 1/1conventional cotton count.
 9. The fire resistant corespun yarn accordingto claim 1, wherein the modacrylic fibers and melamine fibers arepresent in the first sheath of blended staple fibers in an amount offrom about 50 to 90% by weight and from about 10 to 50% by weight,respectively, based on the total weight of the first sheath.
 10. A fireresistant corespun yarn, comprising: a two-plied core of a hightemperature resistant continuous filament comprising fiberglass and alow temperature resistant continuous filament synthetic fiber selectedfrom the group consisting of polyethylene, nylon, polyester andpolyolefin; a first sheath of blended staple fibers surrounding thecore, the fibers comprising modacrylic fibers and melamine fibers; and asecond sheath of staple fibers surrounding the first corespun yarn,wherein the core is from about 15 to 35% by weight based on the totalweight of the corespun yarn, and the second sheath is from about 35 to80% by weight based on the total weight of the corespun yarn.
 11. A fireresistant fabric, comprising: a fire resistant fabric substrate, thesubstrate comprising: a fire resistant corespun yarn, the yarncomprising: a core of a high temperature resistant continuous filamentcomprising fiberglass; a first sheath of blended staple fiberssurrounding the core, the fibers comprising modacrylic fibers andmelamine fibers; and a second sheath of staple fibers surrounding thefirst corespun yarn.
 12. The fire resistant fabric according to claim11, wherein the core further comprises a low temperature resistantcontinuous filament synthetic fiber selected from the group consistingof polyethylene, nylon, polyester and polyolefin, two-plied with thefiberglass filament.
 13. The fire resistant fabric according to claim11, wherein the second sheath staple fibers are of a material selectedfrom the group consisting of cotton, wool, nylon, polyester, polyolefin,rayon, acrylic, silk, mohair, cellulose acetate, and blends thereof. 14.The fire resistant fabric according to claim 13, wherein the core isfrom about 15 to 35% by weight based on the total weight of the corespunyarn, and the second sheath is from about 35 to 80% by weight based onthe total weight of the corespun yarn.
 15. The fire resistant fabricaccording to claim 11, wherein the fabric is free of a fire resistantcoating.
 16. A product upholstered with the fire resistant fabric ofclaim
 11. 17. The product of claim 16, wherein the fabric is free of afire resistant coating.
 18. The product of claim 16, wherein the productis a composite chair, a mattress or a panel fabric furniture system. 19.The product of claim 16, wherein the fabric is free of a barrier fabric.20. The product of claim 16, wherein upon exposure of the fabric toflame, the first sheath is effective to partially burn and char aroundthe core, thereby preventing rupture and creating oxygen depletion tothe product below the fabric.